DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if...
-
Upload
helen-benson -
Category
Documents
-
view
217 -
download
1
Transcript of DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if...
![Page 1: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/1.jpg)
DNA Organization
6.5
![Page 2: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/2.jpg)
Chromosome Structure
• the human genome consists of 23 pairs of chromosomes
• if all of the DNA was stretched out, it would measure 1.8 metres in length
• how does it fit into a typical human cell nucleus, 10 micrometres in diameter?
![Page 3: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/3.jpg)
Hierarchical Organization
• DNA is coiled around a group of 8 stabilizing proteins called histones, forming nucleosomes
![Page 4: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/4.jpg)
Chromosome Structure
• solenoid = a group of 6 nucleosomes coiled into chromatin fibres
• chromatin fibres fold into final chromatin structure through supercoiling.
![Page 5: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/5.jpg)
Chromosome StructureSee animation: http://www.biostudio.com/c_%20education%20mac.htm
![Page 6: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/6.jpg)
Prokaryotic DNA
• primary DNA is single circular chromosome
• supercoiling also in prokaryotes
• plasmids are other circular pieces of DNA that can be exchanged through conjugation
![Page 7: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/7.jpg)
DNA Replication & Aging
6.6
![Page 8: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/8.jpg)
Telomeres
![Page 9: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/9.jpg)
Telomeres
• non-coding, repetitive sequences at the ends of chromosomes
• protect chromosomes from degradation, fusing to other chromosomes, assist in DNA repair
![Page 10: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/10.jpg)
Telomere Shortening
• during replication, the 5’ primer on each strand is removed but not replaced with DNA
• telomeres shorten after each replication
• after many replications, telomeres will eventually disappear, allowing coding DNA to be damaged
![Page 11: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/11.jpg)
Cell Senescence
• period in a cell’s lifespan when it loses the ability to divide & grow
• Hayflick limit = total number of times a normal cell can divide (about 50 in humans)
![Page 12: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/12.jpg)
Dolly the Sheep
![Page 13: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/13.jpg)
Telomerase
• enzyme that adds more DNA to shortening telomeres
• produced in germ line cells, stem cells, certain white blood cells
• cancer cells produce large quantity of telomerase
![Page 14: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/14.jpg)
Anti-Aging
![Page 15: DNA Organization 6.5. Chromosome Structure the human genome consists of 23 pairs of chromosomes if all of the DNA was stretched out, it would measure.](https://reader036.fdocuments.us/reader036/viewer/2022062517/56649ee05503460f94bf07e1/html5/thumbnails/15.jpg)
Dani Walker “Stop Aging Now TS-X Telomere Supplement”